R65 Engine types

[RichieHJ]

R65 Lovers,

Thank you to Justin for adding me to the forum.  I have recently taken possesion of a BMW R65 (1981) and I am looking to do a little maintenance on it before hitting the streets.  The bike has been part of a private collection and has been sat in line in a barn, without use, for many months.  I am currenlty in France and I'm trying to look up on Autodoc the vehicle so I can buy some standard parts.  My first hurdle is to identify the Engine Type from a drop down menu.  Can anyone shed some light on which engine I may have in this frame?  I can dismiss some options, due to the year, but otherwise I'm struggling.  The previous owner didn't know and the Power rating is not recorded on the vehicle registration document.  there is a stamped number on the engine block, by the oil filler cap: Engine Block 6314625.  Frame Number, on a plate: 6314623

The choices on the Autodoc site are as follows (CV is french for HP):

Choose an engine
R 65 (248) (20 KW / 27 CV) (01.1978 - 07.1985) 650ccm
R 65 (248) (20 KW / 27 CV) (04.1985 - 06.1993) 650ccm
R 65 (248) (33 KW / 45 CV) (01.1978-07.1985) 650ccm
R 65 (248) (35 KW / 48 CV) (06.1985 - 10.1988) 650ccm
R 65 (248) (37 KW / 50 CV) (01.1981 - 09.1983) 650ccm
R 65 G/S (247E) (20 KW / 27 CV) (01.1980 - 09.1988) 650ccm
R 65 LS (37 KW / 50 CV) (03.1981 - 03.1985) 650ccm

[georgesgiralt]

Hello,
Realoem.com give an engine made in June  1981. So your engine is a 50 CV post 1981 one.
IT is funny to note the frame and engine number not matching but very close ... First time I've heard of this. Maybe a swap of engine at the factory ?
If the bike sat unused for a long time, you may have dried gaskets so clean the bike as thoroughly as possible and, when running it, check for oil leaks.
And do not forget to post pictures, now and once put back to a nice status.


Edit : It is easy to actually see what engine model you have. Look at the air filter. If it is black and square, your model is post 1981 so has an engine around 50 CV output. Otherwise, it is a pre 1981....

[Barry]

I've used Autodoc for my car parts but I had no idea they did parts for our bikes.  A quick look suggests what they have is very limited and not particularly low priced.  I'd be inclined to check other sources as well.